Floor machine



Dc., 29, H, s, Boum-ON 2,065,560

FLOOR MACHINE Filed July 5, 1935 Patented Dec. 29,l 1936 UNITED STATES PATENT OFFICE 6 Claims.

My invention relates to iloor surfacing machines and particularly to a machine adapted for use in troweling the surfaces of cementitious, plastic and similar materials.

It is customary to use a machine including a motor-driven disc for floating the surface of cementitious materials, the disc having a convex contacting surface. However, it has not been considered possible to trowel a surface by power means as distinguished from the slow and 1aborious process of hand troweling.

I have discovered that a much superior door surface may be secured by the use of a motor driven, rotatable disc having a substantially planar contacting surface. I am able, by the use of such apparatus, to accurately trowel and finish a floor surface with a substantial saving in time and labor. Not only is the use of such a machine more economical than the hand method, but the results secured are measurably better, both in the degree of compactness secured and the more perfectly level character of the finished floor.

An important point in connection withI the use of a machine such as herein described is in the character oi the surface relative to the fine and coarse particles of the mixture. In the working of cement yfinish floor, there is a. tendency to bring to the surface the fine particles of sand in the mix. Of course a certain small proportion of the fines in the surface is desirable in order to insure a smooth finish, b ut if more than the actual minimum required for that purpose are brought to the surface, it will wear easily and have a tendency to become dusty. If the fines in the surface are limited and the finish is level with the top points of the coarser sand particles,vthe wearing qualities of the oor will be much superior.l

Hand troweling has the effect of bringing the nnef'aggregates to the surface, whereas opera-- tion by the rotary motion of the relatively heavy machine has the opposite tendency. This results in the production of a floor `surface that is inherently superior so far as wearing qualities are concerned. As stated, this isV believed to be brought about by the use of a machine in which the troweling action is eiected by a rotating action, continuous in one direction, andadapted to be propelled over the surface in a plane. The reason for this unusual effect is not now thoroughly understood but undoubtedly has a relation to known physical laws.V Of course, one reason for the absence of an excess of iines in the surface following the use Of the machine is that the floor may, for machine troweling, be Aallowed to set to a greater extent before the troweling action is started than would be possible in the case of hand troweling. Furthermore, the floor may be finished more uniformly throughout a relatively large area because` of the fact that troweling may be completed by the use of the machine in a much shorter time than in the case of hand troweling. Thus the mixture may be allowed to set to a more ideal point before starting the troweling action than in the case of hand troweling.

The best and most level surfaces are obtained where ilat troweling is done;` that is, where cocking of the trowel is avoided. However, this result is secured with difficulty even among skillful Operators and an object of the invention is to provide means whereby a thoroughly compacted, evenly flat surface is assured that isnot dependent on operation by a highly skilled mechanic. The construction of the machine is such that a thoroughly satisfactory surface is secured regardless of the previous skill and experience of the operator as a hand troweler.

One reason for the successful operation ofthe motor driven trowelling plate is that the weight, and consequently the pressure imposed on the cement surface is uniform and may be predetermined. It will be noted that the motor and its associated parts are .superimposed on the plate and that the operating handle is so arranged that the operator can neither add to nor detract from the pressure. It may, furthermore, be found desirable to increase the pressure in later stages of the trowelling, by adding a weight to the structure.

It is essential in the operation of any trowelling device that the operating surface of the trowelling plate be maintained in the. desired plane of the finished floor. .This result is inherent in the structure proposed, fortwo reasons: First, because of the relatively large area and the suction developed between the plate and the floor, making it diicult for the operator to maintain the structure in other than a plane corresponding to the surface of the material, and; second, because of the gyrosoopic action of the rapidly rotating plate, as the result of which it is extremely difcult to change the plane of rotation of the plate.

As an incident to the use of the described apparatus and in order to secure thebest results, I provide resilient means in the connection between the motor and the plate or disc. This serves to avoid vibrations that would interfere with the most desirable operation. As a further advantage in operation, I provide means that will serve to reduce the vacuum created between the disc and the surface operated on.

The invention will be more readily understood by reference to the accompanying drawing in which,

Fig. 1 is an elevation of apparatus constructed in accordance with my invention;

Pig. 2 is an enlarged sectional view through the troweling disc;

Fig. 3 is a top plan view of'the disc and its connecting plate; and

Fig. 4 is a detailed plan view showing the form of connection between the disc assembly and the driving head.

In the drawing I have illustrated the apparatus as including a housing Il containing a motor, having a drive shaft Il. An operating handle I2 is connected .to the housing and a cable i3 transmits electric power to the motor.

Connected to the shaft Il by means of a nut Ila is a driving head il having a plurality of equally angularly spaced apertures il therein. One part of the aperture is of a size suflicient to admit the head oi a connecting bolt il while the two ends of the aperture are of reduced sise to conform substantially to the shank of said bolt. The bolts I6 engage in a supporting plate .Il for the troweling disc il, a section of rubber il or similar resilient material being interposed between the driving head i4 and the supporting plate I1. The shape of the apertures I5, as shown, is preferable in order that, in assembling, the bolt I6 may be seated ineither end of the aperture corresponding to the direction of drive of the motor.

The troweling disc il as best shown in Fig.

2 has a central axial opening 20 therein, thev material surrounding the opening being bevelled or rounded for an obvious purpose.V This is= likewise true at the periphery of the disc. 'Ihis y opening insures freedom from excessive suction and the results secured by the vuse of a disc 'so formed, so far as troweling is concerned, are

v very satisfactory. By cutting out the center of the disc I avoid a twisting action that would...

otherwise occur, that would tend to agitate the.` plastic material as distinguished from smoothing or ironing it. Furthermore, the provision for the central cutout area adds to the useful life of the disc in the `matter of wear. Obviously, the distance traveled by the disc in contact with the surface varies from zero at the center or axis, to the maximum at the periphery; and consequently the wear on the disc is in the same proportion. By cutting'out the center, a large part of the area that is subject to slight wear is eliminated, the wear of the remaining portion is more even and a plate can be used for a much longer time without replacement. In the absence of this provision the plate or disc would rather quickly assume the shape of a cone and its effectiveness for trow'eiing would be gone.

The' connection between the'plate Il .and the disc I8 is preferably in the form of bowed or arched spring metal pieces 2l, eight 'being shown in the illustration. 'Ifhese are loined to the plate Il by means of the bolts 21 and ,to the ii by welding at one or both ends of the pieces. These members together with the rubber section i9 provide a resilient connection to the superimf posed frame and motor structure and serve to take up vibrations therebetween.

It will be noted that the bottom or iioor-j contacting surface of thedisc Il is-in a substantialiyy true plane and this should be maintained', 'as nearly as possible asin no other manner can proper btroweling or ironing" be secured. It is also obvious that a material should be used .for the disc that will furnish a' very smooth and polished surface: furthermore, such a material should be' resistant to wear. 's steel havingasubstantialcomponentofnickelorasimilar element that will insure density and hardness is recommended. A formula for a steel of the recommended quality will be later supplied.

0f course, it will be understood that fairly good results may be secured by the use of ordinary steel in the disc and by omitting the cut-out area at the center. Also that other modifications may be made that will occurfto thoseskilledintheartintheoperationoffthe device. Therefore, I do not wish to be limited except as indicated in the appended claims.

- I claim: g

LInatroweling devicefornnishingthesurface of cementitious and similar materials, the combination of a disc having asmooth operating surface i'inisbedto a substantially true plane,

a prime mover superimposed on the disc for rotatingthesame,andresilientmeansinthe connection between the motor and disc. l 2. In a. troweiing device for finishing the surface of cunentitious and similar materials, the combination of a disc having'a smooth operating surface finished to a substantially true plane and having an axial cut-out area, and a prime mover superimposed on the disc for rotating the same, said disc being composed of a relatively dense and hard metal to provide a smooth surface. and to resist wear, the arrangement of the parts normally tending to maintain the face of the disc pdrallel'to the plane of the surface being finished and the weight of the motor and'its supporting parts acting to maintain a uniform downwardly-applied pressure on the trowelingl disc.

3. The method of troweling a cementitious floor whichconsists in laying the floor and preparing it for' troweling, then allowing the cement .in the door surface'to set beyond the point at which hand troweling would be practical, and then troweling the floor by passing over the same a driven at member that is rotated in one direction in a plane. 4. In Aa trowelling device for finishing the surfaceof a cement door, the combination of a disc having van operating'surface nnished to a substantially true plane, a prime mover superfimposed on said 4disc for rotating the same.vand

means for manually directing said trowelling device over' a door, the arrangement .of the parts being such-that, aui'iiform predetermined weightis'applied to said disc during the process of trowelling.

s. m a troweung `device :6r nmsmn'g me survice over a hoor. `thearranieinentv of the parts being s uch `that a uniform predetermined weight is applied to said disc during the process' of troweling. ,l

6. The method'of a cementitious, floor which consistsin laying. the door and' preparingit for troweling, then allowing 'the cement in the floor surface to set beyond the point at which hand troweling vwould be prac tical, and then troweling the floor by' passing over the same a driven fiat member that is rof tated in one direction, and maintaining a sube stantially uniform downwardlydirected prea-v sureon said fiat member.

l Hsnonp s.- noUL'roN. 

